Digital Multimeters 
  Maintenance 
37 
Maintenance 
XWWarning 
To avoid possible electric shock or personal 
injury, repairs or servicing not covered in 
this manual should be performed only by 
qualified personnel as described in the 
27 II/28 II Calibration Information. 
General Maintenance 
Periodically wipe the case with a damp cloth and mild 
detergent. Do not use abrasives or solvents. 
Dirt or moisture in the terminals can affect readings and 
can falsely activate the Input Alert feature. Clean the 
terminals as follows: 
1.  Turn the Meter off and remove all test leads. 
2.  Shake out any dirt that may be in the terminals. 
3.  Soak a clean swab with mild detergent and water. 
Work the swab around in each terminal. Dry each 
terminal using canned air to force the water and 
detergent out of the terminals. 
Fuse Test 
As shown in Figure 10, with the Meter in the  
function, insert a test lead into the  jack and place the 
probe tip on the other end of the test lead against the 
metal of the current input jack. If “LEAd” appears in the 
display, the probe tip has been inserted too far into the 
amps input jack. Back the lead out a bit until the message 
disappears and either OL or a resistance reading appears 
in the display. The resistance value should be as shown 
in Figure 10. If the tests give readings other than those 
shown, have the Meter serviced. 
XWWarning 
To avoid electrical shock or personal injury, 
remove the test leads and any input signals 
before replacing the battery or fuses. To 
prevent damage or injury, install ONLY 
specified replacement fuses with the 
amperage, voltage, and speed ratings shown 
in Table 9.